Coke is a solid carbon fuel and carbon source used to melt and reduce iron ore in the production of steel. During an iron-making process, iron ore, coke, heated air and limestone or other fluxes are fed into a blast furnace. The heated air causes combustion of the coke which provides heat and a source of carbon for reducing iron oxides to iron. Limestone or other fluxes may be added to react with and remove the acidic impurities, called slag, from the molten iron. The limestone-impurities float to the top of the molten iron and are skimmed off.
In one process, known as the “Thompson Coking Process,” coke used for refining metal ores is produced by batch feeding pulverized coal to an oven which is sealed and heated to very high temperatures for 24 to 48 hours under closely controlled atmospheric conditions. Coking ovens have been used for many years to covert coal into metallurgical coke. During the coking process, finely crushed coal is heated under controlled temperature conditions to devolatilize the coal and form a fused mass having a predetermined porosity and strength. Because the production of coke is a batch process, multiple coke ovens are operated simultaneously, hereinafter referred to as a “coke oven battery”.
At the end of the coking cycle, the finished coke is removed from the oven and quenched with water. The cooled coke may be screened and loaded onto rail cars or trucks for shipment or later use or moved directly to an iron smelting furnace.
Coal particles or a blend of coal particles are charged into hot ovens on a predetermined schedule, and the coal is heated for a predetermined period of time in the ovens in order to remove volatiles from the resulting coke. The coking process is highly dependent on the oven design, the type of coal and conversion temperature used. Ovens may be adjusted during the coking process so that each charge of coal is coked out in approximately the same amount of time.
Once the coal is coked out, the coke is pushed from the coke oven into a hot car wherein the coke is broken up and quenched with water to cool the coke below its ignition temperature. The quenching operation must be carefully controlled so that the coke does not absorb too much moisture. Once it is quenched, the coke is screened and loaded into rail cars or trucks for shipment.
One of the problems associated with the coke making process is dusting problems associated with quenching the coke as it is discharged from the coke ovens. During discharge of the coke from the coke ovens, a slab of coke breaks up and drops into a hot car. As the coke drops into the hot car, a significant amount of coke dust is created. Elaborate dust collection systems have been devised to capture dust particles generated as the coke is pushed into the hot cars. In order to reduce the dusting problems associated with coal coking without significantly increasing coke oven cycle times, improved methods for quenching coke are needed.
In accordance with the foregoing need, the disclosure provides a method and apparatus for making coke from coal. The method includes pushing a unitary slab of hot coke onto a substantially planar receiving surface of a hot car. The hot car containing the coke is then transported to a quench car station. The unitary slab of hot coke is pushed onto a substantially planar receiving surface of a quench car at the quench car station. Quenching of the slab of hot coke is conducted in the quench car with a predetermined amount of water. After quenching, the quenched coke is dumped onto a receiving pad for collection thereof.
Another embodiment of the disclosure provides a method of making coke from coal. The method includes burning a bed of coal in a coking oven for a period of time and under reducing atmosphere conditions to provide a unitary bed of coke. A product door from a product end of a first coking oven and a hot car is positioned adjacent the product end of the first coking oven. The unitary bed of hot coke is pushed onto a substantially planar receiving surface of the hot car. The hot car containing the unitary of hot coke is moved to a quenching car station. The product door is reinstalled onto the product end of the first coking oven. In the quenching car station, the unitary bed of hot coke is pushed onto a substantially planar receiving surface of a quench car. The unitary bed of hot coke is quenched in the quench car with an amount of water sufficient to fracture substantially all of the unitary bed of hot coke and to cool the hot coke to a predetermined temperature. The quenched and cooled coke is dumped onto a coke receiving pad.
Still another embodiment of the disclosure provides a hot car for a coke oven. The hot car has a partially enclosed hot box having a substantially planar coke slab receiving surface. An elevation and translation mechanism is provided on the hot car for elevating the hot box and moving the hot box toward and away from the coke oven.
Still another embodiment provides a stationary pusher for pushing a substantially unitary coke slab off of a hot car onto a quench car. The pusher includes a water cooled ram head, a first arm attached to the ram head, and a second arm pivotally connected to the first arm. A gear drive mechanism provides a device for moving the first and second arms. A cooling spray system for cooling the hot car movably is attached adjacent to the ram head. A guiding track is provided for guiding movement of the second arm from a substantially vertical position to a substantially horizontal position.
Another embodiment provides a multifunction quench car having a tiltable receiving bed having a substantially fixed end wall, a substantially fixed side wall, a movable side wall and a movable end wall. A tilting mechanism is provided for tilting the receiving bed in a first direction for quenching coke and in a second direction for discharging quenched coke onto a coke receiving dock.
The method and apparatus described above provide unique advantages for coking operations. In particular, flat pushing of the coke onto a hot car significantly reducing an amount of coke dust generated during a coke oven discharge operation. Accordingly, dust collection equipment for collecting coke dust during the coke discharge operation may be substantially smaller and may provide higher dust collection efficiencies. Another advantage of the of the disclosed embodiments is that a consistently low moisture content of the coke may be achieved.